This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. We have developed a diffusing probe, which can be used in combination with diffuse optical spectroscopic (DOS) methods, to noninvasively determine full spectrum optical properties of superficial in-vivo skin in the wavelength range from 650-1000 nm. This new probe relies on a simple two-layer diffusion model to determine tissue absorption and reduced scattering coefficients.